This disclosure relates to custom-molding in-ear headphone ear tips, and in particular, to using UV-cured elastomer to form an ear tip.
In-ear headphones often include an interface to the ear called an ear tip. The ear tips are generally either a universal design, providing one or more sizes for a user to choose from, possibly made of a compliant material that will partially conform to users' ears, or they are custom molded. Custom-molded ear tips offer the potential advantage of providing a better seal, more reliable fit, and increased comfort. They may fit deeper into the ear canal than a universal tip design, providing improved audio quality, seal, and retention. In addition to earphones, custom-molded ear tips are also generally used for hearing aids.
Custom-molded ear tips tend to be made of hard plastic, which can actually result in decreased comfort if the shape of the ear varies from when the ear tip was molded, due, for example, to motion, activity, heat, sweat, or age (especially for a young user who will grow during the time the ear tip is in use). Forming a custom-molded ear tip generally involves multiple steps: first, a temporarily-liquid material is placed into the ear (or a semi-liquid material or liquid in a compliant container is inserted), and allowed to solidify to the shape of the ear (i.e., by cooling or curing in place). This positive mold then removed and used to form a negative mold corresponding to the ear itself, which is in turn used to form the actual earpiece. This process is generally carried out by a skilled technician or, especially for fitting hearing aids, an audiologist, and may have a turnaround time of one day or longer.
U.S. Patent application publication 2016/0317352 describes using a photo-curable polymer to mold an ear tip in-situ.